Electrostatic chuck and manufacturing method thereof

Abstract

An electrostatic chuck of a stack structure includes a metal layer interposed between insulating layers and a groove formed at a peripheral portion of the electrostatic chuck to have a thickness gradually increasing toward an outside, the groove being covered with a thermally sprayed insulating film. The thermally sprayed film covers at least a portion of the metal layer exposed at an inside of the groove such that the thermally sprayed film does not protrude from the groove.

What is claimed is: 
     
       1. An electrostatic chuck having a stack structure, comprising:
 a metal layer interposed between insulating layers, 
 wherein a groove is formed at a peripheral portion of the electrostatic chuck and includes a groove portion extending outwardly beyond an end of the metal layer, wherein the groove portion has a thickness increasing toward an outside of the groove, the groove being covered with a thermally sprayed insulating film, 
 wherein upper and lower walls of the groove include upper and lower surfaces of the insulating layers respectively above and below the metal layer, and wherein at least one of the upper and lower surfaces of the insulating layers includes at least one of: (a) a curved surface which is curved relative to a top surface of the metal layer, (b) an inclined surface which is inclined relative to the top surface of the metal layer, and 
 wherein the thermally sprayed insulating film covers at least a portion of each of the upper and lower surfaces of the insulating layers in the groove. 
 
     
     
       2. The electrostatic chuck of  claim 1 , wherein the thermally sprayed film covers at least a portion of the metal layer at an inside of the groove such that the thermally sprayed film does not protrude from the groove. 
     
     
       3. The electrostatic chuck of  claim 1 , wherein the metal layer is a conductive layer or a uniform heating layer. 
     
     
       4. The electrostatic chuck of  claim 1 , wherein a cross section of the groove has a shape selected from the group consisting of a funnel shape, a parabolic shape, a shallow dish shape with a flat bottom, an elliptical arc shape, and a circular arc shape. 
     
     
       5. The electrostatic chuck of  claim 1 , wherein the thermally sprayed film is a ceramic insulating film comprising alumina. 
     
     
       6. The electrostatic chuck of  claim 1 , wherein the thermally sprayed film is formed by thermally spraying yttrium oxide. 
     
     
       7. The electrostatic chuck of  claim 1 , wherein a surface of the thermally sprayed film is ground. 
     
     
       8. The electrostatic chuck of  claim 1 , wherein the metal layer has a thickness of 1.0 mm or less. 
     
     
       9. The electrostatic chuck of  claim 1 , wherein the thermally sprayed insulating film covers at least a portion of a side surface of each of the insulating layers and an entire surface of the metal layer and does not extend to a bottom surface of a lower one of the insulating layers. 
     
     
       10. The electrostatic chuck of  claim 1 , wherein each of the upper and lower surfaces of the insulating layers in the groove includes at least one of said curved surface or said inclined surface. 
     
     
       11. The electrostatic chuck of  claim 1 , wherein immediately beneath the groove, a surface of an insulating layer portion is not covered by the thermally sprayed insulating film, and wherein the thermally sprayed insulating film does not extend beyond a bottom wall of the groove. 
     
     
       12. The electrostatic chuck of  claim 1 , wherein a cross section of the groove has a curved shape with a flat base. 
     
     
       13. The electrostatic chuck of  claim 1 , wherein a total length along a base and side walls of the groove is 1.42 mm or more.